ROKS MITRIS

FEATURE 

Terrestrial Satellite Reception 

ROKS MITRIS 

• Easy way to provide large areas with TV 

• Utilizes existing satellite TV reception technology 

• Technically feasible solution using prefabricated 

components for all different kinds of terrain and service 

areas 

• Large bandwidth for up to 300 TV channels 

68 TELE-audiovision International — The World‘s Largest Digital TV Trade Magazine — 07-08/2014 — www.TELE-audiovision.com 

www.TELE-audiovision.com — 07-08/2014 — TELE-audiovision International — 全球发行量最大的数字电视杂志 69

FEATURE 

Terrestrial Satellite Reception 

Satellite Frequencies 

Transmitted 

Terrestrially 

Vitor Martins Augusto 

1 

When a provider wants to bring their 

digital TV programming to their customers, 

there are several ways to do 

this: via satellite, via cable or terrestrially. 

Each one of these methods comes 

with advantages and disadvantages. 

With satellite a provider can broadcast 

to large areas all at once and there 

are enormous bandwidths available 

which, in turn, results in extra costs 

and, depending on the type of content 

that is transmitted, may also require 

encryption. 

Not only that, the bandwidth on 

the most popular satellites is already 

booked. 

A cable network gives the provider 

the ability to offer additional services 

such as telephone and Internet, in addition 

to normal TV, through a return 

channel. Yet the installation of all the 

cabling brings with it very high costs 

and really only makes sense in areas 

with higher population densities. 

Terrestrial transmissions take place 

using a network of reduced-power antennas. 

Even here it becomes problematic 

to provide TV service to large regions 

because the ratio of the number 

of customers to the number of broadcast 

antennas needed is not profitable. 

Far more relevant is the fact that terrestrial 

TV such as DVB-T/T2 in many 

2 

1. Satellite TV reception from a terrestrial 

antenna. The principle behind MITRIS: 

a terrestrial transmitter using satellite 

frequencies 

2. Typical infrastructure for MITRIS. 

Content is streamed to a multiplexer and 

then modulated to DVB-S/S2. Transmission 

is made through omni-directional 

terrestrial antennas, instead of uplinking 

to a satellite. Reception, however is not 

different from a traditional satellite TV. Just 

point the dish to the transmitter antenna. 

countries is only allotted a minimum 

amount of bandwidth and the VHF/UHF 

frequency bands are used for other 

mobile services such as LTE. 

The answer for some time has been 

MMDS. This acronym stands for Multichannel 

Multipoint Distribution Service. 

It has to do with terrestrial transmission 

in the 2.5 to 2.7 GHz frequency 

range. 33 channels, each with 6 MHz 

bandwidth can be transmitted (in the 

USA it‘s only 31 channels) in this higher 

frequency range. What‘s special about 

this is the modulation of the digital 

signal: just like with cable it‘s either 

64QAM or 256QAM. But since there are 

already other services in use in this 

frequency band, MMDS was expanded 

out of which came, among other things, 

MITRIS. 

MITRIS stands for Microwave Inte- 

standard satellite broadcast. 

The frequency band used by MITRIS 

is also used for satellite reception. If 

the antennas transmitting the MITRIS 

signals are located too close to the satellite 

antennas disturbances can ocurr, 

especially in high geographic latitudes 

where the satellite antennas have a low 

elevation. 

A solution to overcome these problems 

is to install the MITRIS antennas 

separate from the satellite antennas or 

by making use of natural reflectors or 

of intentionally putting up reflectors. In 

any event, installing a MITRIS systems 

requires careful planning to not disturb 

satellite signals. 

In exactly the same way that the 

same frequency band from different 

satellites can be used independently 

from each other, MITRIS can also be 

used without having to worry about different 

signals, i.e. satellite and/or MI- 

TRIS interfering with each other. 

This is a great way to utilize the limited 

availability of frequency bands making 

MITRIS the ideal solution for TV distribution 

in rural areas and even more 

so in mountaines regions with its many 

natural obstacles which can be used favorably 

as a reflector to tune out undegrated 

Tele Radio Information System 

and operates in the Ku-band satellite 

frequency range. Another advantage 

over the original MMDS is the output 

transmission power used: it is lower 

(less than 10 mW) with almost the 

same coverage. 

Because of this, MITRIS antenna 

masts can be installed very close to 

residents without incurring any of the 

dxrawbacks that would result from 

excessive radio waves. Naturally, this 

simplifies the setup of MITRIS and simultaneously 

reduces the costs involved 

since antennas can be mounted, 

similar to mobile telephone services, on 

existing structures. 

With a bandwidth of 800 MHz, significantly 

more channels can be broadcast 

with MITRIS in the 11.7 to 12.5 GHz 

frequency band since it has enough 

room for up to 25 transponders. This 

would yield an impressive 200 to 300 

TV channels depending on the bandwidth 

and modulation used. 

It should be pointed out that MITRIS 

does not transmit a polarized signal so 

it doesn‘t matter if the LNB operates 

in the horizontal or vertical position. 

For this reason only half as many transponders 

are available compared to a 



3 

sired signals. 

The company ROKS took the MITRIS 

system and expanded it marketing it 

under the name MITRIS-CS; the CS 

stands for Cellular Structure and refers 

to the ability to operate any number of 

relay stations. 

Implementation is ingeniously simple: 

the transmission system, in which 

the incoming TV signals are combined 

via a multiplexer, optionally encrypted 

with a DVB scrambler and finally modulated 

to DVB-S/S2, functions exactly 

the same as in any satellite station except 

with MITRIS-CS the signal is not 

uplinked to a satellite in geostationary 

orbit, rather, the signal is broadcasted 

terrestrially using omni-directional an- 

tennas. 

The end user receives these signals 

with a standard satellite system including 

a satellite antenna that is instead 

pointed horizontally at the provider‘s 

transmission antennas. 

In other words, it‘s pointed to a transmission 

antenna mast instead of up to 

a satellite. There‘s only one restriction 

and it‘s the same restriction you would 

have with normal satellite reception: 

there must be a clear line-of-sight view 

between the transmission and receiving 

antennas. 

If this is not the case or if a larger 

region needs to be covered, relay stations 

can be utilized with MITRIS-CS. 

Through specially developed ROKS directional 

antennas additional transmission 

towers can be supplied with the 

MITRIS-CS signal which would then retransmit 

the signal to end-users using 

omni-directional antennas. 

In order for this to work, two different 

frequency bands must be used, 

each with 800 MHz bandwidth: one for 

the directional antenna and at the same 

time the other for the omni-directional 

antenna. If both of the transmissions 

were in the same frequency band, the 

differing transmission times would lead 

to significant interference similar to 

the all-too-familiar echoes in DVB-T/T2 

SFNs (Single Frequency Networks). 

Since the Ku-band already utilizes two 

frequency bands (Low Band: 10.7-11.5 

GHz and High Band 11.7-12.5 GHz), it 

made sense for ROKS to use it also for 

their MITRIS-CS. The Low Band is used 

for the relay stations while the High 

Band is used by the end-users. Why? 

It‘s very simple: the lower the frequency 

the further the transmission 

propagation at the same output power. 

It‘s for this reason that ROKS uses 

the lower frequency band for their directional 

antennas while the end users 

utilize reception systems with the 22 

kHz switching signal turned on in the 

High Band. The LNBs ROKS distributes 

actually are for the high-band only. 

Calculations show that MITRIS-CS is 

the most cost-effective way to broadcast 

TV content: if you consider both 

the costs to build the infrastructure 

and operate the system, the result is 

the lowest price per channel. This type 

of system is also advantageous for end 

users since they would be able to use 

standard satellite systems for reception. 

How do you build such a MITRIS- 

CS system? ROKS, the inventor of the 

MITRIS-CS system, was founded in 

5 

4 

1994 and therefore brings 20 years of 

experience to the table. This company 

already claims several patents in the HF 

sector to their name. 

Their businesses include research, 

3. ROKS developed their own 

antennas to handle frequencies of 

11-12GHz. Here you see antennas 

used for repeaters. 

4. What if you need to cover bigger 

regions? No problem, just use 

repeaters! 

5. Another example of an 

implementation. The head station 

receives different transponders 

over satellite and uses a combiner/ 

multiplexer to create the provider’s 

bouquet. Channels can be 

encrypted. The resulting stream is 

then up-modulated and transmitted 

through an omni-directional 

antenna to subscribers in the 

11.7-12.2 GHz band, while a second 

directional antenna transmits the 

stream in the 10.7-11.5 GHz band 

to a relay antenna. Here, the signal 

is up-converted again to 11.7-12.5 

GHz and transmitted through the 

antenna to the subscribers. 

Notice the relatively low power 

used. 

development and manufacture of microwave 

products for various applications 

but primarily it‘s the implementation 

of the entire MITRIS infrastructure 

from broadcasting via radio relay up to 

the headend. 

It must be emphasized that the system 

includes the word “information”. 

This means that the MITRIS system 

was not just meant as a system to 

transmit TV broadcasting but also as a 

data transmission system. 

In the beginning, it was used for 

analog broadcasts with some data 

transmissions in parallel. With the 

introduction of digital tv the tv signals 

and data signals merged and the 

amount of data signals increased. 

Eventually we will see the TV broadcast 

part of the signal disappear and move 

over to IPTV, thus making the MITRIS 

system to a data-only environment for 

the transfer of high data rates. 

ROKS’ product palette is quite extensive: 

LNBs, antennas, multiplexers, en- 

coders, decoders, encryption systems, 

modulators, etc. 

This allows ROKS to offer complete 

MITRIS-CS distribution systems that 

are based as much as 70% on their own 

hardware. 

With customers all over the world 

from Algeria to Kenya to Spain, ROKS- 

TV has become a globally powerful 

company with their one-of-a-kind TV 

distribution solutions. 

MITRIS-CS is a very interesting alternative 

to standard TV distribution 

technology; it makes it possible to supply 

TV services inexpensively to people 

outside of larger city areas. 

Because the MITRIS-CS infrastructure 

is based in large part on existing 

technology and makes use of standard 

satellite reception equipment, the costs 

for end-users would also be quite low. 

Thanks to this technology, ROKS has 

become the reference company and is 

the first contact when it comes to the 

setup of a MITRIS based network.

ROKS MITRIS

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